Treatment of rubber



Patented Dec. 14, 1948 "Iii suit a tailor 1 am tel-w dece sed, late of Al nnfolll-o, by fggexfeollltrix, Akron, Ohio, assignor ffi Emit Goiioration, Akron, Ohio, a corl'voi'l l'fiavilni. .lipplication Julyz. 1945,- 'S'efial'No. 602,935

'fiti'or'i relates "t6 the preservation of faster) arid-iii e ar marl-y nae tr ilwcasser 'a'gfes'istrs" for f'fififi'f.

Many materials have been employed tiiiiii prove the resistance of rubber to deterioration rhre'sultingiproduct:isitetraliydrpahiienaphthoquinoile; more exactly,- t io;5l8j8a=tetrahydrc=l,4= naphthoquinone. This is a pale yellow; crystal line material melting gat BS-160 e6; gand extremely soluble "in benzene. The preparationifif this ma= terial is illustrated by the following example:

Example 1 Fifty-five grams of p-beiifioliiii'ri'ori f-iver suspended in 100 cc. of benzene .and,.butadiene gas was bubbled intbth'e mixture'untilthebottle and contentszincreased in weight by ahiiut-8235 grams. The mixture was then ralluwed ito rstaritl for 5 days at room temperature withaoccasional shaking. 'The 'beiiz'oiilinone slowly disappeared, havin'g ibne completely into 'solution arter es-aye. The benzene was -thendistilled fr'm the :selatlan aha the vl'iqillid residue was cooled. 'Wheil-iifitllization began, several volumes of petroleum ether were added. The crystals were filtered oil and washed with more petroleum ether. Seventyeight grams of gray crystals were obtained, amounting to 96 percent of the theoretical yield.

In addition to the parent butadien-1,3, employed in the foregoing example, compounds in which one or more of the hydrogens is replaced by a substituent group may also be used; Further examples are isoprene; 4-methyl-L3-pentadiene; 1,3-.pentadiene and 1-phenyl-1,3-butadiene.

Various other 1,4-quinones mayalso be used,

including 1,4-naphthoquinone, 1,4-phenanthra- ,quinone :and 1,-4-anthraquinone. .Alsoqtlre quinones may :c'ont-ainvarious substituents much alkyl, aryl, aralkyl, halogen, hydroxyl and similar such substituted compounds being equivalents of the parent compounds .iior' parposes of this invention. I

; 'Tetrahydro 'm naphtnoqulnones obtained as flli Example 1 will further react with *butaalenes at somewhat elevated temperaturesg to produce polyhydroanthra'quin'olles, "fer example, at about ilm- G. .At isuch tempratui'ei' the.reaction :is carried out under "pressure iII-ibfdf to prevent loss of material. ;.Alternajtively, one moi of the p=beilzoqliinone maybe :lea'cted aundersmlilareonditions of temperature and pressure-with two mols or a 1,3-butadiene. I Thus, p-benzoquinone and butadiene-L3 willyield the octohydroanthraquinon'ebfthe following lcrlaula:

Il 1. EC

The products obtained by the reaction of 1,4- quino'nes' and 1,3-butadiens may be designated tetrahydro polycyclic -quinones. In accordance with this ,terminology, the 'octahydroanthraquinone formed-by thereaction of :one nlol :of 1pbenzoquin'one .with two molsof butadiene-LB may :be regarded as 1a di(tetrahydro) polycyclic quithe temperature running up to 110-115 C. while a mass of white crystals separated. These, after cooling, were filtered off and washed with petroleum ether. The yield was 24 grams or 92.5 percent of the theoretical; The crystals melted at about 1208-209? and were quite sparingly soluble in the usual solvents. The reaction in volved may be represented as follows:

4 in which R is an aryl radical having the hydroquinone hydroxyl groups attached to the ring ad- J'acent the ring.

2. A method of treating rubber which comprises vulcanizing. it in the presence of a dihydro-1,4- naphthohydroquinone.

3. A method of preserving a rubber composition which comprises incorporating therein a 5,8-cli- I hydro-1,4-dihydroxynaphthalene.

These hydroquinones are very effective age resisters for rubber. Thus, the product of Example 2 ,was incorporated into rubber as an age resister in accordance with the following formula:

. N Parts by weight Extracted pale 'crepe 100.0 Zinc oxide 5.0 Sulfur. 3.0 Hexamethylene. tetramine 1.0 Stearic acid 1.5 Age 'reslster 1,0

The. compounded stock Was vulcanized for various periods at 285 F. and samples were tested before and after ageing for six days in an oxygen bomb at 50 C. and 150'pounds per square inch pressure. Results were as fOllOWS:

Cure in A Ultimate Ultimate Modulus minutes Tensile in Elongation at 500% at 285 F. KgmJcm. in percent elongation Before Ageing After Ageing These results compare very favorably with those obtained Withphenyl-beta-naphthy1amine, an outstanding'commercial age resister.

This application is a continuation-in-part of co-pending "application Serial No. 498,397, filed August 12, 1943, now Patent No. 2,379,460, granted July-3, 194s."

What is claimed is:

l.- A method of treating rubber which comprises vulcanizing it in the presence of a dihydro polycyclicvprhydrcquinone of condensed ring structure having the formula 1 4. A method of treating rubber which comprises vu-lcanizing it in the presence of 5,8-dihydro- 1,4-naphthohydroquinone.

5. A rubber product which has been vulcanized in thepresence of a dihydro polycyclic p-hydroquinone of condensed ring structure having the formula r in which R is an aryl radical having the hydroquinone hydroxyl groups attached to the ring adjacent the REFERENCES CITED 1 The following referencesare of record in the file ofthis patent:-'

'UNITED STATES PATENTS Date Number, i Name 2,363,687 Paul NOV. 28, 1944 2,379;460 Scott July 3, 1945 

